It is also referred to as Central America, the latter of which also includes Panama, El-Slavador. Please see link for detailed information. Note, Mexico is a part of North America and perhaps the difference here lies in the fact that parts of Mexico is included in Meso-America.

I might add this quote from the link cited:
" there was a nation of Central America in the early 19th century, consisting of the present day nations of Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica (and a portion of the modern Mexican state of Chiapas). This was sometimes known as the United Provinces of Central America or the United States of Central America.

The related term Mesoamerica (occasionally also called "Middle America") is used in English mostly restricted to referring to the Pre-Columbian Native American cultures of this region, which extended north into central Mexico."

I think that should pretty much answer your question.


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Note added at 36 mins (2005-07-04 10:46:20 GMT)
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You could call it أمريكا الوسطى التاريخية. I hope this would help.

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Note added at 2 days 14 hrs 50 mins (2005-07-07 00:59:37 GMT)
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أو أمركا الوسطى الحضارية